Field of the Invention
This invention relates generally to marine retaining walls. More specifically, the invention concerns caissons for retaining artificial islands used in offshore drilling and production operations and their method of construction. The caissons of this invention have broad application for artificial island construction in the Arctic and in many other environments.
The main problems encountered in constructing a caisson (sheet or sheet piling) retained Arctic gravel island for drilling and production operations are: (1) elaborate construction aids would need to be created to handle and efficiently emplace the long slender sheets in 40 feet and greater water depths, (2) more accurate pile alignment would be necessary than is normal offshore--any misalignment would be difficult and time consuming to correct, and (3) failure to complete the construction in the summer season would result in severe ice damage--some bulkhead design concepts involve driving 600 sheet piles.